Despite intensive research efforts, the exact risk factors associated with lateral ankle sprains (LAS) and anterior cruciate ligament (ACL) injuries remains elusive. We hypothesize that lower extremity injuries (e.g., LAS and ACL injuries) are multifactorial in nature, with a combination of structural alignment, neuromuscular strength, and dynamic movement patterns playing a critical role. A standardized pre-season screening assessment program for the identification of risk factors for lower extremity injury in the collegiate athlete population will be studied. The study will examine combined risk factors for ankle sprains and anterior cruciate ligament injuries to ascertain the factors that contribute to these acute repetitive (ankle sprains) and highly debilitating (anterior cruciate ligament tears) in a physically active population. The risk of osteoarthritis and subsequent loss of function is inherent in any physical activity. The goal of this study is to determine what modifiable factors play a role in lower extremity injury with the intent of creating an intervention program aimed at reducing occurrence and intensity of injury across various populations (e.g., school aged children and military recruits). The study will use a prospective cohort design and will initially enroll 200 student-athletes at five U.S. NCAA Division I universities. Each study participant will undergo a baseline assessment that includes measurement of structural alignment, neuromuscular factors, and dynamic movement patterns. The participants will be followed for up to 2 years with prospective identification of lateral ankle sprains and anterior cruciate ligament injuries. The focus of this pilot prospective study is to establish the feasibility and procedures for a large multicenter cluster group study intended to ascertain the risk factors for a variety of lower extremity injuries across multiple universities. Ultimately, the research will make a significant contribution to our understanding of the causes of lower extremity injury, with this portion of the study specifically focusing on acute lateral ankle [unreadable] sprains and anterior cruciate ligament injury. [unreadable] [unreadable] [unreadable] [unreadable]